The primary symptoms of attention deficit disorder (ADD)/attention deficit hyperactivity disorder (ADHD) include a persistent pattern of inattention, hyperactivity, and/ or impulsivity. The symptoms can appear individually, or in combination (Grohol, J., 2007). The disorder is diagnosed using the American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5, 2013). In order for a person to qualify as having ADD/ADHD, they must have had symptoms evident before age 12. However, children do not “grow out of” the disorder; it affects both children and adults. According to the DSM-5 criteria, an adult must meet 5 or more and a child must meet 6 or more of the symptoms for at least 6 months to qualify as having ADD/ADHD. The disorder has a negative impact on the affected person's social, academic, and occupational functioning. In addition, 20%-30% of children with ADD/ADHD also have a learning disability, including dyslexia (Martin, B., 2007). Other people with ADD/ADHD have associated conditions such as Tourette's Syndrome, oppositional defiant disorder, conduct disorder, anxiety, depression, or bipolar disorder.
There are many theories regarding the cause of ADD/ADHD. It has a strong genetic basis. The primary genes involved with the cause of ADHD are involved with the brain's ability to produce dopamine, as people with ADD/ADHD typically have decreased levels of dopamine in the brain. Some experts believe that some food additives and sugar exacerbate the condition. However, sugar is not a primary cause of the disorder. Other research indicates that a lack of omega-3 fatty acids (which are important for brain development and function) may be causal of ADD/ADHD symptoms. The addition of fish oil supplements appear to alleviate the disease symptoms in some children, and may boost their scholastic performance. Other factors considered causal for ADD/ADHD include maternal smoking. Women who suffer from ADD/ADHD are more likely to smoke than women without the disorder; therefore, a genetic link cannot be excluded.
The Centers for Disease Control and Prevention (CDC) quotes ADD/ADHD as one of the most prevalent childhood disorders affecting an estimated 6.4 million children (aged 4 to 17years) have been diagnosed in the US in 2011. The percentage of children with ADD/ADHD has increased from 7.8% in 2003 to 9.5% in 2007 to 11% in 2011 (CDC ADHD data and statistics, 2011). The incidence in adults with ADD/ADHD was reported as 4% to 5% in 2011 (Antshel et al. BMC Medicine 2011). The disorder is more prevalent in males, children, people with chronic health problems, dysfunctional families, and lower-income families.
Children and adults with ADD/ADHD are treated with the same medications. Parents of children aged 4 to 17 years diagnosed with ADD/ADHD reported that 6.1% were being treated with medications for the disorder in 2011 compared to 4.8% in 2007 (CDC ADHD: United States, 2003-2011). Effective behavior management techniques are also useful training techniques for children with ADD/ADHD (Antshel et al., 2011). Typical ADD/ADHD medications used to treat ADD/ADHD are categorized in one of four classes of medications: stimulants, (amphetamine or methylphenidate), nonstimulants (including some antihypertensives/central alpha-adrenergic agonists), antidepressants (tricyclics), and atypical antipsychotics. Typical medications used to treat ADD/ADHD currently on the market that are stimulants include amphetamine, dextroamphetamine mixed salts (Adderall®) and dextroamphetamine (Dexedrine®); typical methylphenidate stimulants include methylphenidate HCl (Ritalin®) and dexmethylphenidate (Focalin®); typical nonstimulants include atomoxetine HCl (Strattera®), guanfacine (Tenex® or Intuniv®), and clonidine (Catapres®); typical antidepressants include bupropion HCl (Wellbutrin®), venlafaxine (Effexor®), and imipramine (Tofranil®); and typical antipsychotics include aripiprazole (Abilify®).
Although there are a wide variety of medications to treat ADD/ADHD, there are some associated risks with some of the approved medications. The FDA has issued a warning about drug abuse with amphetamine stimulants. There is also a concern regarding the possibility that all amphetamine and methylphenidate stimulants used for ADD/ADHD may increase the risk of cardiac and psychiatric adverse events. The antidepressants used to treat ADD/ADHD have shown an increased risk of suicide in adults, especially in the first 1-2 months of treatment (Grohol, J., 2007).
Only 25% of children treated with medications for ADD/ADHD have a modest improvement (Antshel et al. BMC Medicine 2011). There is also a challenge in optimizing the benefit/risk ratio of treatment with careful adjustment of dosages and combined therapy for comorbid conditions, such as depression (Martin, B., 2007). Even with the knowledge gained to date regarding the disorder and the medications available, the disorder is difficult to treat effectively. There is poor compliance to treatment and the psychiatric comorbidities that complicate successful outcomes for patients with ADD/ADHD.
There is a need for a new drug with an acceptable efficacy and reduced adverse effects than the currently available therapies for treating ADD/ADHD.